Fuse guard for cutouts



Feb. 15, 1949. c H D 2,461,898

FUSE GUARD FOR CUTOUTS Filed Dec. 19, 1947 [NVENTOB David C Hubbard (lilo/neg UNITED STATES PATENT OFFICE FUSE GUARD FOR CUTOUTS David C. Hubbard, Centralia, M0., assignor to A. B. Chance Company, Centralia, Mo., a corporation of Missouri Application December 19, 1947, Serial No. 792.804

lever or ejector.

Another object is the provision of a leader guard which may be so mounted that it can be moved out of the way into another position when the fuse tube is being provided with a new fuse.

Another object is the provision of a fuse guard which is adapted to deflect the leader from its engagement with the throw-out lever when the fuse melts, and which is adapted to retain the leader hanging from the guard below the fuse tube.

Another object is the provision of a fuse guard which is provided with a movable part adapted to be used to release the fuse leader from the guard, this part being a part of every guard and being so arranged that there is no possibility of rattling which might cause a static disturbance.

Still another object is the provision of a fuse leader guard or leader holding device which is simple in construction, sturdy, capable of economical manufacture and which is adapted to be attached to the standard fuse tubes of the prior art without affecting the normal operation of a fused drop-out cut-out to which it is attached.

Other objects of the invention will be apparent from the following description and the accompanying drawings, in which similar characters of reference indicate similar parts throughout the several views.

Referring to the single sheet of drawings accompanying the specification,

Fig. l is a fragmentary side elevational view of the fuse tube of a fused drop-out cut-out, having its lower opening fitting provided with a fuse guard embodying the invention;

Fig. 2 is a fragmentary front elevational View of a modification, which includes a movable element adapted to be used in releasing the fuse leader from the guard;

Fig. 3 is a fragmentary side elevational view of the guard of Fig.2;

Fig. 4 is a fragmentary side elevational view of a modification;

Fig. 5 is a. fragmentary front elevational view of this modification;

Fig. 6 is a fragmentary front elevational view of another modification adapted to defiect the leader from engagement with the ejector leader when the fuse is blown;

Fig. 7 is another fragmentary side elevational view of another modification; and

Fig. 8 is a fragmentary front elevational view of the modification of Fig. 7.

Referring to Fig. 1, it! indicates a fuse tube unit of a fuse cut-out drop-out which is closed at its upper end and open at its lower end, and provided at its lower end with a metal contact fixture H.

The metal contact fixture II has a bore IL for receiving the insulating tube [0 to which it is secured by a plurality of pins !3. The fixture II has a pair of depending side flanges l4 and a curved back wall 15 forming a guard or baffle wall for directing the gases away from the operator, the right side and bottom of this fixture being open.

The fuse tube unit fixture I i may also be provided with a lateral extension it upon which is pivoted a spring pressed throw-out lever l l. The fuse has its upper end secured in the top of the fuse tube unit I0, and its leader extends out of the aperture IS in the bottom of this unit and about a groove or pin I 9 at the end of the throwout lever H, the end of the leader being finally secured by a clamping nut 20.

The present leader guards may be utilized with fuse tube units of the type having a throw-out lever as well as those which do not have a throwout lever. The fuse leader guard of Fig. l is indicated in its entirety by the numeral 25, and may consist of a strip of hard drawn springtempered steel which has been bent to substantial U-shape by means of an easy bend 22 at the juncture of the two legs 23, 24.

The legs 23, 24 of the leader guard 2! may diverge from the bend 22 until the obtuse bend 25 in each leg brings the end portions 26 into substantial parallelism when they are mounted on the fuse tube. The legs 23., 24 are initially so bent toward each other that they must be spread to put the guard on the fuse tube fixture where the legs of the guard press together to be retained upon trunnions.

The trunnions on the fuse tube lower fixture H are indicated by 21, and they may consist of integral laterally projecting aligned lugs having an outer cylindrical portion 28 and an inner rectangular extension 29. The rectangular extension 29 is located close to the flat sides of the fixture II, and the rectangular extension 29 extends downwardly in the direction in which the guard is to be held in fixed position.

The guard 2! has each of its legs 23, 23 provided with a D-shaped aperture 3|, the apertures 3| being in alignment with each other and having their fiat side lowermost. Thus the apertures 3| are adapted to fit upon the combined round and rectangular inner portion of each trunnion 21, engaging the flat sides 3!! of the fixture H, the complementary squared portions preventing any pivotal movement of the guard.

In this position the guard is located down-- wardly and toward the right of the discharge aperture IS in the fuse tube in position to receive and, retain the leader, but not necessarily in alignment with the fuse tube. Thus the blast guard l5 directs the blast and leader outwardly toward the right. The legs 23, 24, may, however,

be sprung apart until the squared portions of the leg apertures SI and trunnions 2? are out of engagement with each other, and then the legs are rotatably mounted upon the rounded portions 28 of the trunnions 21.

The guard may be pivoted counterclockwise to- Ward the right and upward out of the way during the re-fusing of the tube. If desired, the guard can also be removed by springing the legs apart.

Each of the legs 23, 24 is also preferably proor hammering element 33, which is rnovably r mounted on the U-shaped bend 22 in such position that it may be used to hammer or force a leader out of engagement with the wedging walls 34 located toward the bottom of the leader guard The anvil 33 may consist of a piece of metal strap having a centrally located rectangular aperture 35 0f sufficient length to receive the U-shaped bend of the leader guard 2!. The aperture 35 is of sufficient width to permit a lateral move ment of the anvil 33 on the U-shaped bend 22, whereby the inner edge 36 of the anvil 33 will engage and dislodge any leader that is wedged between the walls 34.

In order to prevent any rattling of the anvil 33 on the leader guard 2 l, a leaf spring 3'i is provided having a central bend 38 engaging the U-shape bend 22 and having each of its ends slotted at 39 to engage on both sides of the anvil 33-. The spring 31 prevents rattling of the anvil and ordinarily holds it in the position of Figure 3.

Referring now to Figures 4 and 5, these show a modified form of leader guard indicated in its entirety by the numeral ifi. The leader guard 40 may be constructed of two identical-stamped metal straps 4|, lZ, welded or riveted together at two parallel end portions 63 at the bottom or it may be a single strap bent to this form. The straps 4|, 42, in this case form a V-shaped opening with a sharper wedging recess 43.

The upper ends of the legs 4 l, 32 form attaching flanges which are parallel to each other, and are apertured to receive the rivet or screw bolts 4% which pass through these attaching flanges and through the side walls it of the lower 4 tube fixture, by means of which the leader guard is pivotally mounted on the blast guard.

The attaching flanges 35 are provided with stop lugs H punched out of the edge of each flange and adapted to engage the lower edge of the blast guard walls M, as shown at the left in Figure 4, to determine the range of pivotal movement of the leader guard. Thus the leader guard may be tilted outwardly toward the right, in Figure 4, out of alignment with the fuse tube but in position to intercept and retain the fuse leader.

The stop lug ll on the right side, in Figure 4, limits the upward pivotal movement in a counterclockwise direction of the leader guard ti), and its presence also makes the two straps identical so that they will both have the left-hand stop member ll which is more important than the right-hand stop member 57. The diagonal position of the leader guard 48, tilted toward the right, also puts it in position to prevent it from interfering with the sweep of the ejector arm 17.

Referring to Figure 6, this is a modification shown in a view similar to Figure 5 of a leader guard 8, which is so constructed that it will defleet the leader from its engagement with the ejector lever ll. In this case the two legs 49, 58 are of unequal length because the leg 59 is straight while the leg 53 extends diagonally downward and over to the leg 59. This locates the inner surface 5! of leg under the leader 52 which passes around a pin 53 carried by the ejector iever ll.

When the leader 52 is blown outward it is deflected toward the left, (in Figure 6) by the surface 52 on leg 53 of leader guard G8.

Referring to Figures '7 and 8, this is a modification in which the leader guard 55 is of a slightly different construction so that it may be attached to the fuse tube units now on the market. The leader guard 5:3 consists of a pair of sheet metal strips 55, 56, bent to form a V-shaped wedging opening 5? between them, and having parallel attaching flanges 58 riveted or welded to ether.

The strips 55, 53 form an obtuse bend at 59 so the upper portions 63 of the strips extend parallel to each other, and these upper portions are long enough to extend up beyond the lower contact fixture ii on the fuse tube so that the upper portions 68 may terminate in clamping band formations 6| which are bent inwardly to fit against the fuse tube 52.

These clamping band formations may have outwardly projecting flanges 63 in front and 64 in back for receiving the-screw bolts 65, by means of which the clamping band formations iii are drawn together to clamp the leader guard on the fuse tube 62.

The present guard includes a further feature in that the legs 55, 5B are wider and extend forwardly beyond the forward edges 68 of the side flanges i i of the blast guard on the lower fixture I I, and the legs 55, 53 have inwardly turned guide flanges 37. These guide flanges 6! present an aperture between them of the full width of the blast guide of the tube, but below the blast guard the side flanges bl" approach each other at 68 and have a downwardly facing shoulder at E9, leaving a diamond pointed recess Fe for retaining the fuse leader by wedging engagement with the V- shaped walls 57.

I At the rear side, however, toward the fuse throwout lever I? the legs 55, 56 present a full opening so that they will not interfere with the fuse throw-cut lever. In this modification it will be noted that the leader guard 54 again extends diagonally forward and toward the right out of alignment with the'fuse tube. but in position to intercept a leader which is directed downwardly and toward the right by the blast guard rear wall l5.

All of the leader guards of Figures 4 to 8 may be provided with apertures 1| in their side walls, these serving as vents for discharging the gas which emerges from the fuse tube. In some embodiments of the invention these vents may not be necessary.

The operation of the present fuse guard will be apparent from the description of their struc ture and the functions of the parts. When the fuse is blown the throw-out lever draws the fuse movable anvil for forcing it out of its wedging recess, and the guard may be pivoted out of the way during the re-fusing of the tube, if desired.

It will thus be observed that I have invented an attachment for fuse tube units of a fused drop-out cut-out which is adapted to intercept the leader of the fuse when it is expelled from the tube, and to retain it by wedging engagement of the leader between two V-shaped walls.

The present leader guards are simple and capable of economical manufacture, and may be attached to all kinds of fuse tube units. The guards do not interfere with the operation of the fuse throw-out lever, and most modifications may be pivoted out of the way during the re-fusing operation.

The guards do not interfere with the expulsion of the gases, and while they do not intercept the molten particles of the fuse they are adapted to intercept the fuse leader and hold it until removed by the operator.

While I have illustrated preferred embodiments of my invention, many modifications may be made without departing from the spirit of the invention, and I do not wish to be limited to the precise details of construction set forth, but desire to avail myself of all changes within the scope of the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States, is:

1. The combination of a fuse tube unit of the type having an insulating tube for housing a fuse, said tube having a. lower metal contact fixture provided with a pivoted fused throwout lever, the fuse having a leader extendin out of the lower open end of the tube and said leader being engaged by said throwout lever, with a fuse guard comprising a substantially V-shaped metal member having diverging legs for engaging each side of the fuse tube unit to support the V-shaped metal member below the open end of the tube, so that the fuse leader when withdrawn from said tube will be guided into the V-shaped restriction of the guard to be wedged therein and held from complete release from the fuse tube unit.

2. The combination of a fuse tube unit of the type having an insulating tube for housing a fuse, said tube having a lower metal contact fixture provided with a pivoted fused throwout lever, the fuse having a leader extending out of the lower guard being pivotally mounted on said contact fixture to be rotated upwardly out of the way during the re-fusing of the unit.

3. The combination of a fuse tube unit of the type having an insulating tube for housing a fuse, said tube having a lower metal contact fixture provided with a pivoted fused throwout lever, the fuse having a leader extending out of the lower open end of the tube and said leader being engaged by said throwout lever, with a fuse guard comprising a substantially V-shaped metal member having diverging legs for engaging each side of the fuse tube unit to support the V-shaped metal member below the open end of the tube, so that the fuse leader when withdrawn from said tube will be guided into the V-shaped restriction of the guardto be wedged therein and held from complete release from the fuse tube unit, the said guard being pivotally mounted on said contact fixture to be rotated upwardly out of the way during the re-fusing of the unit, the said guard being provided with punched stop members adjacent the upper end of one of its legs for engagement with the contact fixture to limit the rotation of said pivotally mounted guard.

4. The combination of a fuse tube unit of the type having an insulating tube for housing a fuse, said tube having a lower metal contact fixture provided with a pivoted fused throwout lever, the fuse having a leader extendin out of the lower open end of the tube and said leader being engaged by said throwout lever, with a fuse guard comprising a substantially V-shaped metal member having diverging legs for engaging each side of the fuse tube unit to support the V-shaped metal member below the open end of the tube, so that the fuse leader when withdrawn from said tube will be guided into the V-shaped restriction of the guard to be wedged therein and held from complete release from the fuse tube unit, the said legs being provided with apertures for exhaust of the gases caused by fusing of the fuse.

5. The combination of a fuse tube unit of the type having an insulating tube for housing a fuse, said tube having a lower metal contact fixture provided with a pivoted fused throwout lever, the fuse having a leader extending out of the lower open end of the tube and said leader being engaged by said throwout lever, with a fuse guard comprising a substantially V-shaped metal member having diverging legs for engaging each side of the fuse tube unit to support the V- shaped metal member below the open end of the tube, so that the fuse leader when withdrawn from said tube will be guided into the V-shaped restriction of the guard to be wedged therein and held from complete release from the fuse tube unit, the said guard being constructed of a single integral strip of metal bent back upon itself into v-shape.

6. The combination of a fuse tube unit of the type having an insulating tube for housing a fuse, said tube having a lower metal contact fixture provided with a pivoted fused throwout lever, the

fuse having a leader extending out of the lower open end of the tube and said leader being engaged by said throwout lever, with a fuse guard comprising a substantially V-shaped metal member having diverging legs for engaging each side of the fuse tube unit to support the V-shaped metal member belew the open end of the tube, so that the fuse leader when withdrawn from said tube will be guided into the V-shaped restriction of the guard to be wedged therein and held from complete release from the fuse tube unit, the said guard supporting at its apex a metal anvil member having an enlarged aperture through which the guard passes, for use in jarring the leader out of wedging engagement with the guard in releasing the leader.

7. The combination of a fuse tube unit of the type having an insulating tube for housing a fuse, said tube having a lower metal contact fixture provided with a pivoted fused throwout lever, 5

the fuse having a leader extending out of the lower open end of the tube and said leader being engaged by said throwout lever, with a fuse guard comprising a substantially V-shaped metal member having diverging legs for engaging each side of the fuse tube unitto support the V- shaped metal member below the open end of the tube, so that the fuse leader when withdrawn from said tube will be guided into the V-shaped restriction of the guard to be wedged therein and held from complete release from the fuse tube unit, the said guard supporting at its apex a metal anvil member having an enlarged aperture through which the guard passes, for use in jarring the leader out of wedging engagement with the guard in releasing the leader, and a leaf spring mounted in said enlarged aperture and engaging the apex of the guard to hold the anvil against rattling or vibration.

8. The combination of a fuse tube unit of the type having an insulating tube for housing a fuse, said tube having a lower metal contact fixture provided with a pivoted fused throwout lever, the fuse having a leader extending out of the lower open end of the tube and said leader being engaged by said throwout lever, with a fuse guard comprising a substantially V-shaped metal member having diverging legs for engaging each side of the fuse tube unit to support the V-shaped metal member below the open end of the tube, so that the fuse leader when withdrawn from said tube will be guided into the V-shaped restriction of the guard to be wedged therein and held from complete release from the fuse tube unit, the said guard supporting at its apex a metal anvil member having an enlarged aperture through which the guard passes, for use in jarring the leader out of wedging engagement with the guard in releasing the leader, and a leaf spring mounted in said enlarged aperture and engaging the apex of the guard to hold the anvil against rattling or vibration, the said leaf spring being bowed outwardly at its middle and having rectangular slots atits ends, said slots engaging the opposite sides of the anvil.

9. The combination or" a fuse tube unit of the type having an insulating tube for housing a fuse, said tube having a lower metal contact fixture provided with a pivoted fused throwout lever, the fuse having a leader extending out of the lower open end of the tube and said leader being engaged by said throwout lever, with a fuse guard comprising a substantially V-shaped metal member having diverging legs for engagin each side of the fuse tube unit to support the V-shaped metal member below the open end of the tube, sothat the fuse leader when withdrawn from said tube will be guidedinto the V-shaped restrictionv of the guard to be wedged therein and held fromcomplete release from the fuse tube unit, the said guard being constructed of a pair of strips of metal welded together at the apex of said V.

10. The combinationof a fuse tube unit of the type having an insulating tube for housing a fuse, said tube having a lower metal contact fixture; provided with a pivoted fused throwout lever, the fuse having a leader extending out of the lower open end of the tube and said leader being engaged by said throwout lever, with a fuse guard comprising a substantially V-shaped metal member having diverging legsfor engaging each side of the fuse tube unit to support the V-shaped metal member below the open end of the. tube, so that the fuse leader when withdrawn from said tube will be guided into the v-shaped restriction of theguard to be wedged therein and held from complete release from the fuse tube unit, the said guard being constructed of spring-tempered steel having its legs initially tensioned to resiliently engage the sides of the contact fixture.

11. The combination of a fuse tube unit of the type having an insulatin tube for housing a fuse, said tube having a lower metal contact fixture provided with a pivoted fused throwout lever, the fuse having a leader extending out of the lower open end of the tube and said leader being engaged by said throwout lever, with a fuse guard comprising a substantially V-shaped metal member having diverging legs for engaging each side the fuse tube unit to supportthe V-shaped metal member below the open end of the tube, so. that the fuse leader when withdrawn from said tube will be guided into the V-shaped restriction of the guard to be wedged therein and held from complete release from the fuse tube unit, the pivotal mounting for said guard comprising a pair of trunnions and apertures for connecting the guard to the contact fixture.

12. The combination of a fuse tube unit of the type having an insulating tube for housing a fuse, said tube having a lower metal contact fixture provided with a pivoted fused throwout lever, the fuse having a leader extending out of the lower open end of the tube and said leader being engaged by said throwout lever, with a fuse guard comprising a substantially V-shaped metal member having diverging legs for engaging each side of the fuse tube unit to support the V-shaped metal member below the open end or the tube, so that the fuse leader when withdrawn from said tube will be guided into the V-shaped restriction of the guard to be wedged therein and held from complete release from the fuse tube unit, the pivotal mounting for said guard comprising a pair of trunnions and apertures for connecting the guard to the contact fixture, the said trunnions being carried by the contact fixture and having a flat-sided portion adjacent the fixture and the apertures being located in the legs and having a flat portion for engagement with the fiat-sided part ofthe trunnion to hold the guard at an angle to the open end of the tube.

13. The combination of a fuse tube unit of the type having an insulating tube for housing a fuse, said tube having a lower metal contact fixture provided with a pivoted fused throwout lever, the fuse having a leader extending out of the lower open end of the tube and said leader being engaged by said throwout lever, with a fuse guard comprising a substantially v s'haped metal member having diverging legs for engaging each side of the fuse tube unit to support the V-shaped metal member below the open end of the tube, so that the fuse leader when withdrawn from said tube will be guided into the vshaped restriction of the guard to be wedged therein and held from complete release from the fuse tube unit, the said contact fixture being formed below the open end of the tube with a blast-directing chute extending at an angle to the axis of the tube, and the guard being held at substantially an equivalent angle in the direction of the blast.

14. The combination of a fuse tube unit for a fused cut-out, said unit having a tube open at its lower end for receiving the fuse and leader and having a contact fixture at its lower end provided with a diagonally extending blast chute, with a fuse guard comprising a substantially V- shaped metal member having bearing apertures adjacent its ends, and laterally projecting trunnions carried by the contact fixture for engagerounded at their outer ends and having a lower rectangular portion, and said trunnions having outer cylindrical portions and inner partially round and rectangular portions.

16. The combination of a fuse tube unit for a fused cut-out, said unit having a tube open at its lower end for receiving the fuse and leader and having a contact fixture at its lower end provided with a diagonally extending blast chute, With a fuse guard comprising a substantially V- shaped metal member having bearing apertures adjacent its ends, and laterally projecting trunnions carried by the contact fixture for engagement in said apertures, the said apertures being rounded at their outer ends and having a lower rectangular portion, and said trunnions having outer cylindrical portions and inner partially round and rectangular portions, the said guard being resilient and tensioned to engage the contact fixture and to engage the trunnions at the rectangular portions thereof except when sprung apart to rotate on the cylindrical portions of the trunnions.

DAVID C. HUBBARD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,955,138 Mangan Apr. 17, 1934 2,094,013 Hill Sept. 28, 1937 

